With rapid development of communications technologies, Long Term Evolution (LTE), which is one of mainstream technologies of a mobile telecommunication system, is widely researched and applied around the world. It is stipulated in an established protocol that, a buffer status report (BSR) is triggered when user equipment (UE) has uplink data available for transmission. If a regular BSR is already triggered and is not canceled and no uplink resource is allocated during a current transmission time interval (TTI), the UE triggers a scheduling request (SR), and then reports the SR at a next SR reporting time. Accordingly, a base station performs uplink scheduling, acquires the BSR, and then schedules, according to the BSR, the to-be-transmitted uplink data.
Specifically, after the UE triggers the regular BSR, the uplink data is sent when the UE receives a uplink grant (UL Grant) delivered by the base station.
In the prior art, if the uplink data contains a BSR MAC control element (MCE), or the uplink data contains all to-be-transmitted data, a current BSR is canceled.
However, in a process of implementing technical solutions in embodiments of the present invention, it is found that in an existing BSR mechanism, no matter whether uplink data is transmitted successfully, a current BSR is canceled provided that the uplink data contains a BSR MCE or all to-be-transmitted data. When a current uplink data transmission fails, for example, the transmission failure is caused by a false alarm or by an insufficient demodulation capability of a base station, the base station no longer performs uplink scheduling for the UE, and the UE no longer sends an uplink SR. The UE can trigger a regular BSR again only when a BSR retransmission timer times out, so as to trigger an SR and obtain a next scheduling opportunity. However, in the protocol, a prescribed duration of the BSR retransmission timer is 320 ms-1024 ms. Once the foregoing transmission failure occurs, an uplink delay of at least 320 ms is introduced, thereby causing a relatively long data transmission delay.